Managing Bluffs, Dunes and Change
Published in Spinsheet - July 2018
Figure 1. Shoreline Evolution. Adapted from “Shoreline Management in Chesapeake Bay” by. Hardaway, C. S., Byrne, R. J. Virginia Institute of Marine Science, College of William and Mary.
In around 500 BC the Greek philosopher Heraclitus said, “There is nothing permanent accept change.” This statement alone could keep me up all night attempting to untie its fullest meaning. ‘Permanent’ is so comfortable, reassuring and fixed. We love permanent. ‘Change’ however, is full of unknowns, counterintuitive to permanent and desperately uncomfortable. Unfortunately, change is also ubiquitous, change is constant and the sooner we embrace the enigmatic nature of change that saturates our life the better. Practically applied? Not so easy.
The philosopher/contractor (me) on summer break, visited last month an investment property that sat on the edge of a 60-foot bluff. Well the house sat on the edge; the deck actually was hanging over the bluff. After another brutal winter of storm and wave action the house was both plunging off the bluff and down in price. I began digging into what it would take to restore the shoreline of this water front property, create a long-term safety solution for the bluff, and secure the home and environment. Despite our experience and previous consulting on situations just like this, it turned out a dynamic learning opportunity. Many phone calls were made to seawall engineers, DEQ, excavating companies, soils experts and low and behold the guy who supplies 80 % off all dune grass/ beach grass (Ammophila breviliguata) to the Great Lakes, and was the last contractor in after Katrina.
The Maryland Chesapeake, coastal bays and tributaries boast about 6600 miles of shoreline with almost 4600 miles of that eroding. 65% has low to moderate erosions, and 3% are experiencing moderate to high erosion (according to the DNR that’s 4 foot a year). I can only guess with 69% of our shores experiencing erosion, in combination with the demand for waterfront property and the obvious development, many of you are participants in this dilemma. According to some estimates a linear foot of shore is valued at about 10K. Suggesting that erosion is impacting about a Billion dollars of shores, natural habitat and our homes. This is no small problem.
In walks the philosopher. If change is the only permanent result, if what I know about dune and wetland habitat is it’s constant shifting and movement, if figure 1 is correct and during the time of Heraclitus Annapolis was inland and Cape Charles didn’t exist, how do I feel about trying to preserve a shoreline at all. Why? Well, those of you who have investments, dreams, amazing views spent beside family know why. And, if we only impact the short-term and a few more generations, why not? Expect shoreline change, anticipate the need to protect your investment but not at the cost of undermining your impact on the Bay environment. Below is a list of things I’ve learned and materials I have found that can be helpful if you find yourself in this same situation and are looking for positive solutions.
You must fix and maintain your property; this isn’t something that will take care of itself. But, more than that it’s not something you do alone. If you fix your property and your neighbor doesn’t (depending on fetch and direction) it can greatly compound the issue by creating counter productive currents. Or if your neighbor does some modifications and you don’t it may increase your deterioration.
Do your homework, find your erosion data based on prominent wind and wave activity as well as soil structure. Do you step down to your beach, is your marsh disappearing, has your neighbor installed shoreline mitigation measures or does your shoreline look like my hairline where it recedes at a shocking rate?
Consider alternations and protection in this order: Nothing, moving buildings and infrastructure, non-structural stabilizations (slope grading, marsh development, beach grass establishment), shoreline structure, offshore structures and breakwater, groins.
When addressing severe erosion problems think of approaching this with multiple solutions. Ideally: shoreline structure, grading with both high and low marshes (min of 10’) meeting your beach grass and dunes (also planted).
Know that wind erosion and wave erosion are two different enemies and need to be treated differently while in conjunction with each other.
Root structure and vegetation is of utmost importance and if you clear your trees to have a view your house could fall in the Bay (example: investment property I noted above). But, even with root structure steep cuts and cliffs can easily get undercut dropping those roots into the water. Watch for undercuts at the bottom of cliffs and non-stable slopes, and know that marshes won’t do the job alone and plan on substantive seawalls (see picture of my spring walk). FYI sea walls can run 1500-2000 a linear foot. Save up.
Manage water. Never grade it over the bluffs and cliffs. Grade away from bluffs into swells and systems that take the surface water down through the soils slowly or in run off systems.
Please don’t plan to do this alone, on the cheap or without permitting. You’re investing in extremely valuable property and long-term impacts in a setting that we all truly love and enjoy. Start by seeking the appropriate consultant.
Lastly please look at this as an opportunity. This can really enhance your experience, develop beaches and habitat where you can enjoy your shore, be beautiful, functional and help revitalize the shore.
See the attached links to help build some of that education.